The present invention relates generally to electric field delivery to a tissue of a patient. More particularly, the present invention provides systems and methods for delivering electric fields to a target tissue of a patient for destruction of cancerous cells and eliciting or induction of a specific anti-cancerous cell immune response in the patient.
The immune system is the body's natural defense against infection and disease, destroying foreign elements such as harmful bacteria and viruses that enter the body. In order for the immune system to provide effective defense against disease, it has to recognize and label agents that are “foreign” and distinguish foreign infection from the body's own non-harmful cells and components. Once this happens, cells in the immune system can function to eliminate the foreign agents.
Another important role of the immune system is to identify and eliminate tumors. The transformed cells of tumors include proteins or antigens that are not found on normal cells. To the immune system, these antigens appear foreign, and their presence causes immune cells to attack the transformed tumor cells. The antigens produced by tumors can have several sources, and may include those derived from a foreign infecting agent, such as a virus, as well as the body's own proteins that have been mutated or altered, or proteins that occur at low levels in normal cells but reach high levels in tumor cells.
One primary response of the immune system to tumors is to destroy the abnormal cells using so called natural killer T cells, sometimes with the assistance of other immune cells, such as helper T cells. Tumor antigens may be processed and presented by immune cells in a similar way to viral or bacterial antigens. This allows immune cells such as killer T cells to recognize the tumor cell as abnormal. In addition, in some instances antibodies are generated against tumor cells allowing for their destruction by the complement system.
While the immune system represents a powerful and vital defense against cancer, in some cases, tumors evade the immune system and go on to become cancers. Thus, there is great interest in cancer immunotherapy treatments and techniques that utilize or stimulate the body's own immune system to better combat and eradicate cancerous cells in the body. Cancer immunotherapy aims to teach the body's own natural defenses to identify cancer cells correctly and then kill them. There are different types of cancer immunotherapy, including cancer vaccines and a treatment called Antigen-Specific Cancer Immunotherapeutics (ASCI).
While cancer immunotherapy holds tremendous promise, to date very few effective treatments have been developed. Thus, there is continued interest in techniques and treatments that can stimulate a patient's immune system to better combat cancerous cell growth.